<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>6.关于打印</title>
  </head>
  <body>
    <script type="text/javascript" >
      let arr = [{x:1,y:2}]

      console.log(arr) //1

      arr[0].x = 100

      console.log(arr)//100
    </script>
  </body>
</html>